ABSTRACT From 2000-2010, the annual number of new HIV diagnoses among MSM aged 13-24 years old more than doubled. There are stark racial and ethnic disparities in the incidence of new HIV infections among YMSM; 13- 24 year old racial and ethnic minority MSM now represent a rapidly growing share of all new HIV infections. Although the likelihood of HIV acquisition is greater at older ages, many of the cognitive and behavioral risk factors that contribute to the risk of HIV infection rates develop in adolescence. As adolescent MSM (AMSM; 13-18 years old) begin to develop and express gender and sexual identities, to experiment and begin sexual behaviors, and to begin to establish a sense of self, there is the opportunity to parallel this period of growth with targeted, tailored interventions that equip AMSM with the life skills they need to reduce their vulnerability to HIV risk and to establish the life skills necessary to manage risk. We developed a mobile-friendly WebApp intervention focused on life skills training (iCON) across 16 topics, ranging from stigma and discrimination to sexual health, with links to local resources. In the proposed activities, we will adapt iCON for four U.S regions heavily impacted by HIV, and revise the content to include materials that are age-appropriate for 13 to 18 year- olds. Given the role that stigma and social isolation plays in the lives of many AMSM, we also propose to embed a peer-to-peer motivational interviewing component to iCON, allowing participants to access motivational interviewing counseling via VSee video-chat. With a large and diverse sample (n=500), we will test the efficacy of the intervention, now referred to as iCON+, on cognitive and behavioral HIV-related outcomes using a two-arm randomized control design. In addition, we examine whether structural characteristics in a region (e.g., race/ethnicity segregation, HIV prevalence) influence the efficacy of the proposed intervention. We propose the following Specific Aims: (1) Adapt a multilevel, online life skills intervention (iCON+) to address HIV vulnerability among AMSM living in four heavily impacted regions constituting diverse racial/ethnic and geographic areas (Chicago-Detroit; Atlanta-Washington, DC; Memphis- New Orleans; San Francisco-San Diego) in the US. (2) Test the efficacy of iCON+, as compared to a delayed intervention condition, to improve cognitive (e.g., comfort discussing sexuality; HIV prevention attitudes, norms, self-efficacy, behavioral intentions) and behavioral (e.g., condom use, HIV testing, PrEP use) factors using a prospective RCT design. (3) Examine the differential efficacy of iCON+ in improving psychosocial mediators (e.g., personal competency) associated with our outcomes and (4) Examine how socio-ecological determinants at the individual (e.g., race/ethnicity, urbanity) and regional (e.g., socioeconomic disadvantage, HIV prevalence) level are associated with iCON+'s efficacy.